691 research outputs found
Chemical synthesis and magnetic properties of monodisperse cobalt ferrite nanoparticles
In this work, a successful synthesis of magnetic cobalt ferrite (CoFe2O4)
nanoparticles is presented. The synthesized CoFe2O4 nanoparticles have a
spherical shape and highly monodisperse in the selected solvent. The effect of
different reaction conditions such as temperature, reaction time and varying
capping agents on the phase and morphology is studied. Scanning transmission
electron microscopy showed that the size of these nanoparticles can be
controlled by varying reaction conditions. Both X-ray diffraction and energy
dispersive X-ray spectroscopy corroborate the formation of CoFe2O4 spinel
structure with cubic symmetry. Due to optimized reaction parameters, each
nanoparticle was shown to be a single magnetic domain with diameter ranges from
6 to 16 nm. Finally, the magnetic investigations showed that the obtained
nanoparticles are superparamagnetic with a small coercivity value of about 315
Oe and a saturation magnetization of 58 emu/g at room temperature. These
results make the cobalt ferrite nanoparticles promising for advanced magnetic
nanodevices and biomagnetic applications.Comment: 10 pages, 9 figure
Effect of vitamin D replacement on maternal and neonatal outcomes: a randomised controlled trial in pregnant women with hypovitaminosis D. A protocol
Introduction: The vitamin D recommended doses during pregnancy differ between societies. The WHO guidelines do not recommend routine prenatal supplementation, but they underscore the fact that women with the lowest levels may benefit most. The effects of routine supplementation during pregnancy on maternal and neonatal clinical outcomes have not been investigated in the Middle East, where hypovitaminosis D is prevalent. Our hypothesis is that in Middle Eastern pregnant women, a vitamin D dose of 3000?IU/day is required to reach a desirable maternal 25-hydroxyvitamin D [25(OH)D] level, and to positively impact infant bone mineral content (BMC).Methods and analysis: This is a multicentre blinded randomised controlled trial. Pregnant women presenting to the Obstetrics and Gynaecology clinics will be approached. Eligible women will be randomised to daily equivalent doses of cholecalciferol, 600?IU or 3000?IU, from 15 to 18?weeks gestation until delivery. Maternal 25(OH)D and chemistries will be assessed at study entry, during the third trimester and at delivery. Neonatal anthropometric variables and 25(OH)D level will be measured at birth, and bone and fat mass assessment by dual-energy X-ray absorptiometry scan at 1?month. A sample size of 280 pregnant women is needed to demonstrate a statistically significant difference in the proportion of women reaching a 25(OH)D level ?50?nmol/L at delivery, and a difference in infant BMC of 6 (10)g, for a 90% power and a 2.5% level of significance. The proportions of women achieving a target 25(OH)D level will be compared between the two arms, using ?2. An independent t test will be used to compare mean infant BMC between the two arms. The primary analysis is an intention-to-treat analysis of unadjusted results.Ethics and dissemination: The protocol has been approved by the Institutional Review Board at the American University of Beirut-Lebanon (IM.GEHF.22). The trial results will be published in peer-reviewed medical journals and presented at scientific conferences.Trial registration number: NCT02434380.<br/
Crash dieting: The effects of eating and drinking on driving performance
Previous research suggests that compared to mobile phone use, eating and drinking while driving is more common and is seen as lower risk by drivers. Nevertheless, snacking at the wheel can affect vehicle control to a similar extent as using a hands-free phone, and is actually a causal factor in more crashes. So far, though, there has not been a controlled empirical study of this problem. In an effort to fill this gap in the literature, we used the Brunel University Driving Simulator to test participants on a typical urban scenario. At designated points on the drive, which coincided with instructions to eat or drink, a critical incident was simulated by programming a pedestrian to walk in front of the car. Whilst the driving performance variables measured were relatively unaffected by eating and drinking, perceived driver workload was significantly higher and there were more crashes in the critical incident when compared to driving normally. Despite some methodological limitations of the study, when taken together with previous research, the evidence suggests that the physical demands of eating and drinking while driving can increase the risk of a crash
Locally recurrent subcutaneous and muscular hydatid cysts of the leg: an unusual case report
We report a rare case of 50-year-old Moroccan woman with local recurrence of a subcutaneous hydatid cyst in proximity to the medial surface of the tibia and another cyst at the tibialis posterior muscle in the absence of liver, lung und spleen involvement. The first surgery was done in another hospital three years ago; no adjuvant treatment was performed after surgery. Recurrence was diagnosed according to the MRI appearance, serological and pathological findings. The patient underwent complete excision of the subcutaneous cyst with two centimeters of the medial gastrocnemius muscle; the tibialis posterior muscle cyst was intraoperatively drained and irrigated with scolicidal agent as it was next to the posterior tibial pedicle. A periopertive anthelmintic chemotherapy was administered. Two years after the patient showed no recurrence. This case report and literature review describe an approach to the diagnosis and management of this pathological entity
The Influence of Supply Chain Management Strategies on Organizational Performance in Hospitality Industry
The studys primary goal is to analyze the connection between SCM practices and organizational performance, and it also aims to evaluate the moderating role of management type. Quantitative data collected from Jordans hotel and restaurant workers via questionnaire. Structural equation modeling is used to examine the hypothesized relationships. Organizational Performance is positively impacted by effective information sharing. Information Quality (IQ) positively affects Organizational Performance (OP), and Strategic Supplier Partnerships (SSP) play a crucial role. Customer Relationship Management (CRM) had no discernible effect on OP, according to the study. OP is positively impacted by Postponement (POS) techniques. When implemented, postponement increases the efficiency of the supply chain and the happiness of guests. Type of Managements moderating effect is investigated. It moderates the effects of Strategic Supplier Partnerships (SSP), Information Quality (IQ), Customer link (CR), and Postponement (POS) on Organizational Performance (OP) but has no effect on the link between Information Sharing (IS) and Organizational Performance (OP). The success of Jordans hotel sector relies in part on how well its supply chain is managed. Insights from this research can help those working in the hotel industry improve supply chain operations and efficiency. Improving guest experiences and being competitive in Jordans fast-paced hospitality industry may be driven through bolstering cooperation, creating strategic partnerships, and investing in information quality
A drug-induced hypotensive challenge to verify catheter-based radiofrequency renal denervation in an obese hypertensive swine model
Objective
Sham-controlled trials provided proof-of-principle for the blood pressure-lowering effect of catheter-based renal denervation (RDN). However, indicators for the immediate assessment of treatment success are lacking. This study sought to investigate the impact of RDN on renal renin arteriovenous difference (renal renin AV-Δ) following a hypotensive challenge (HC).
Methods
Twelve hypertensive Ossabaw swine underwent either combined surgical and chemical (n = 3) or catheter-based RDN (n = 9). A telemetry monitor was implanted to acquire hemodynamic data continuously. Before and after RDN, a sodium nitroprusside-induced HC was performed. Renal renin AV-Δ was calculated as the difference of plasma renin concentrations drawn from the renal artery and vein.
Results
In total, complete renal renin AV data were obtained in eight animals at baseline and six animals at baseline and 3 months of follow-up. Baseline renal renin AV-Δ correlated inversely with change in 24-h minimum systolic (− 0.764, p = 0.02), diastolic (r = − 0.679, p = 0.04), and mean (r = − 0.663, p = 0.05) blood pressure. In the animals with complete renin secretion data at baseline and follow-up, the HC increased renal renin AV-Δ at baseline, while this effect was attenuated following RDN (0.55 ± 0.34 pg/ml versus − 0.10 ± 0.16 pg/ml, p = 0.003). Renin urinary excretion remained unchanged throughout the study (baseline 0.286 ± 0.187 pg/ml versus termination 0.305 ± 0.072 pg/ml, p = 0.789).
Conclusion
Renin secretion induced by HC was attenuated following RDN and may serve as an indicator for patient selection and guide successful RDN procedures
Effect of Arteriovenous Anastomosis on Blood Pressure Reduction in Patients With Isolated Systolic Hypertension Compared With Combined Hypertension
Background: Options for interventional therapy to lower blood pressure (BP) in
patients with treatment‐resistant hypertension include renal denervation and
the creation of an arteriovenous anastomosis using the ROX coupler. It has
been shown that BP response after renal denervation is greater in patients
with combined hypertension (CH) than in patients with isolated systolic
hypertension (ISH). We analyzed the effect of ROX coupler implantation in
patients with CH as compared with ISH. Methods and Results: The randomized,
controlled, prospective ROX Control Hypertension Study included patients with
true treatment‐resistant hypertension (office systolic BP ≥140 mm Hg, average
daytime ambulatory BP ≥135/85 mm Hg, and treatment with ≥3 antihypertensive
drugs including a diuretic). In a post hoc analysis, we stratified patients
with CH (n=31) and ISH (n=11). Baseline office systolic BP (177±18 mm Hg
versus 169±17 mm Hg, P=0.163) and 24‐hour ambulatory systolic BP (159±16 mm Hg
versus 154±11 mm Hg, P=0.463) did not differ between patients with CH and
those with ISH. ROX coupler implementation resulted in a significant reduction
in office systolic BP (CH: −29±21 mm Hg versus ISH: −22±31 mm Hg, P=0.445) and
24‐hour ambulatory systolic BP (CH: −14±20 mm Hg versus ISH: −13±15 mm Hg,
P=0.672), without significant differences between the two groups. The
responder rate (office systolic BP reduction ≥10 mm Hg) after 6 months was not
different (CH: 81% versus ISH: 82%, P=0.932). Conclusions: Our data suggest
that creation of an arteriovenous anastomosis using the ROX coupler system
leads to a similar reduction of office and 24‐hour ambulatory systolic BP in
patients with combined and isolated systolic hypertension. Clinical Trial
Registration: URL: http://www.clinicaltrials.gov. Unique identifier:
NCT01642498
The evolution of the Aristolochia pallida complex (Aristolochiaceae) challenges traditional taxonomy and reflects large-scale glacial refugia in the Mediterranean
The taxonomy of the Mediterranean Aristolochia pallida complex has been under debate since several decades with the following species currently recognized: A. pallida, A. lutea, A. nardiana, A. microstoma, A. merxmuelleri, A. croatica, and A. castellana. These taxa are distributed from Iberia to Turkey. To reconstruct phylogenetic and biogeographic patterns, we employed cpDNA sequence variation using both noncoding (intron and spacer) and protein-coding regions (i.e., trnK intron, matK gene, and trnK-psbA spacer). Our results show that the morphology-based traditional taxonomy was not corroborated by our phylogenetic analyses. Aristolochia pallida, A. lutea, A. nardiana, and A. microstoma were not monophyletic. Instead, strong geographic signals were detected. Two major clades, one exclusively occurring in Greece and a second one of pan-Mediterranean distribution, were found. Several subclades distributed in Greece, NW Turkey, Italy, as well as amphi-Adriatic subclades, and a subgroup of southern France and Spain, were revealed. The distribution areas of these groups are in close vicinity to hypothesized glacial refugia areas in the Mediterranean. According to molecular clock analyses the diversification of this complex started around 3–3.3 my, before the onset of glaciation cycles, and the further evolution of and within major lineages falls into the Pleistocene. Based on these data, we conclude that the Aristolochia pallida alliance survived in different Mediterranean refugia rarely with low, but often with a high potential for range extension, and a high degree of morphological diversity.Turkish Science Foundatio
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